The present invention relates to a multi-mode cellular phone terminal supporting a plurality of communications systems.
While cellular phone terminals supporting a variety of communications systems including the PDC (Personal Digital Cellular) system, CDMA (Code Division Multiple Access) system, and GSM (Global System for Mobile Communication) system, these communications systems are different in terms of communications procedure, signal processing details, frequency band and bit rate. To perform communications/conversation with such different cellular phone terminals, it is necessary to provide a cellular phone terminal supporting each communications system.
In the related art, in order to support a plurality of communications systems via a single terminal, hardware and software to support individual communications system have been provided and such hardware and software are accommodated in a single terminal. That is, in the related art, terminals supporting two communications systems are accommodated in a single cellular phone terminal for the user to select either of the terminals to support the communications systems in use.
A related art multi-mode cellular phone terminal supporting a plurality of communications systems houses hardware of two terminals. Thus, such a terminal has more parts and more necessary memory capacity than the single-mode cellular phone terminal. It is difficult to scale down the size of the terminal and accordingly, the cost is higher.
In recent years, a cellular phone terminal in greater need that allows voice calls as well as high-speed data communications via connection to the internet. In particular, a multi-mode cellular phone terminal is in need supporting a communications system for voice calls and a system for high-speed data communications, and featuring a compact design and low cost.